1. Field of the Invention
The present invention relates to a sample processing system and a sample processing method for a trace detector.
2. Description of the Related Art
A trace particle or liquid sample collected from a surface of an object under inspection can be tested by means of trace detection techniques. The trace detection techniques are particularly suitable for detection of harmful substances of trace level such as explosives, narcotics, chemical warfare agents, and biological warfare agents formed in the form of particles, aerosols, or liquid droplets.
The ion mobility spectrometry (IMS) is one of the trace detection techniques and is disclosed in patents such as U.S. Pat. Nos. 3,699,333 and 4,777,363. An example of the operation mode of an ion mobility spectrometer is shown in FIG. 1. Through forty years of research, rapid progress has been made in the equipment design, separation principle, and sampling techniques associated with IMS as disclosed in U.S. Pat. Nos. 4,311,669, 4,551,624, DE 19502674, and WO 9306476. Sampling techniques are mainly divided into non-contact sampling as disclosed in U.S. patent application Ser. No. 2006249671, and U.S. Pat. Nos. 6,870,155 and 5,425,263, and wipe sampling as disclosed in U.S. Pat. No. 5,859,375, and U.S. patent application Ser. Nos. 20060192098 and 20050288616.
FIGS. 1-5 are schematic diagrams showing conventional wipe sampling introduction method. As shown in FIGS. 2-5, a trace detector 10 comprises an ion mobility spectrometer 12 and a sample feeding device 14′ for feeding a sample substrate 1 into the trace detector 10. A sampling substrate 1 collects a sample by contacting with a surface to be tested, and then is fed into the sample feeding device 14′ and heated by a heater 3′ therein to release (evaporate) the sample.
As shown in FIG. 4, for example, the ion mobility spectrometer 12 may comprise a sample gas inlet 16, an ion source Ni63 18, an ion gate 24, electrodes 22, a grid 26, and an ion detector 20.
FIGS. 2 and 3 are schematic diagrams showing conventional wipe sampling introduction method. As shown in FIGS. 2 and 3, the sample feeding device 14′ comprises a part 2′. The part 2′ is disposed on an side of the sample feeding device. The part 2′ can be opened and closed, or drawn out of and pushed into the sample feeding device. The sample feeding device further comprises a heater 3′ for evaporating a sample from a sample substrate 1. A sampling substrate 1 collects a sample by contacting with a surface to be tested, and then fed into the sample feeding device and heated by heater 3′ therein to release (evaporate) the sample.
By using the prior art sample processing method, the sampling substrate is heated directly in order to evaporate the sample. Most types of sample substrates will release interference substances to disturb the detection. It has proved to very difficult to find a proper material which has both high collection efficiency by swipe sampling and desired high temperature resistance.